Sports drinks are electrolyte replacement beverages needed by athletes to replace water, salts and energy during exercise. While for exercise that lasts for less than one hour, plain water is enough to replace fluid losses, it is not the case for high-intensity endurance exercise like long-distance cycling, running and heavy weight training etc.
It is extremely important to replenish fluid losses during exercise to prevent dehydration. Even small losses of body fluid can cause headaches, lack of concentration, decreased reaction time, lethargy, and can hinder sporting performance. Fluid losses of just 2-3 per cent of fluid can lower performance by almost 20 per cent.

Sweat rates vary among athletes and requirements must be computed individually. Thirst is not a good indicator of fluid needs. The best way to assess hypo-hydration is to weigh the athlete before and after exercise. One kg of body weight lost equals loss of one litre of water. Suitable fluid replacement is absolutely necessary. Approximately 150-200 ml / every 15- 20 minutes must be consumed to avoid dehydration. Cool liquids are better absorbed and must be sipped, not gulped.

Sweat is made of water along with three minerals known as electrolytes — sodium, chloride and potassium. Electrolytes have many functions in the body including maintaining water balance, helping your muscles (including your heart) contract and relax and helping transmit nerve impulses. The sodium also helps your body absorb and retain water and triggers your thirst mechanism to make you drink more. Sports drinks are designed to meet these losses as they contain sodium chloride (10-25 mmol of sodium/litre) and potassium chloride. The inclusion of sodium and flavouring in sports drinks has been shown to improve fluid intake, making it easier for athletes to achieve fluid intake goals.

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